Add automatic header checks and formatting

[arjkesh]

Description

• Add new utility script to check for license headers, as well as automatically write them out if they don't exist
• Update format.sh to run this action in addition to ruff
• Update infra tests to run the --check action to confirm that headers exist

CI Configuration

config:
  build: false
  # valid options are "ops" and "benchmark"
  test: []

Checklist

• Code formatted and imports sorted via repo specifications (./format.sh)
• Documentation updated (if needed)
• CI configuration reviewed

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[arjkesh]

/ok to test bc6a980

[hannahli-nv]

LGTM, thx!